A collagen thin film-based bioimpedance sensor for cell proliferation rate assessment

In this paper, a bioimpedance sensor used to measure the impedance behavior of the biological cells cultured on a scaffold of collagen thin films. The collagen thin films with different concentrations were created on a 1-hexadecanethiol modified surface of the interdigitated electrodes(IDEs). The mesenchymal stem cells(MSCs) and human umbilical vein endothelial cells(HUVECs) were cultured on the collagen thin films. The interaction and the proliferation rate of these cells were investigated by the microscopic, and bioimpedance approaches. Results showed that the MSCs, and HUVECs excellently attached to the collagen thin films. Impedance measurements of the cells cultured on the collagen thin film were performed by a Hioki IM3570 impedance analyzer at the frequency band of 10 kHz to 1MHz at 10 mV. Bioimpedance measurements showed that the proliferation rate of both MSCs, and HUVECs increased by decreasing the collagen thin films concentration. After 48 h, the differential impedances (ΔΖ ) of the MSCs cultured on the collagen thin layers with concentrations of 250μg/mL,500μg/mL , and 1000μg/mL measured 3.09Ω≤Δ≤48.03Ω, 2.62Ω≤Δ≤45.79Ω, and 1.9Ω≤Δ≤25.22Ω, respectively. Also, ΔΖ of the HUVECs obtained 27.3Ω≤Δ≤39.2Ω, 8.25Ω≤Δ≤18.43Ω, and 0.96Ω≤Δ≤9.6Ω for the corresponding frequency band and collagen thin films concentrations.